CN111095640A

CN111095640A - Method for manufacturing membrane electrode assembly and stacked body

Info

Publication number: CN111095640A
Application number: CN201980004460.2A
Authority: CN
Inventors: 金志轩; 金度莹; 杨栽春
Original assignee: LG Chem Ltd
Current assignee: LG Chem Ltd
Priority date: 2018-01-19
Filing date: 2019-01-15
Publication date: 2020-05-01
Anticipated expiration: 2039-01-15
Also published as: EP3664209A4; KR20190088723A; EP3664209A1; KR102203974B1; WO2019143097A1; JP7069505B2; CN111095640B; EP3664209B1; US11302946B2; JP2020534645A; US20200274180A1

Abstract

The present specification relates to a method of manufacturing a membrane electrode assembly and a stacked body. Specifically, the present specification relates to a method of manufacturing a membrane electrode assembly including an anode, a cathode, and an electrolyte membrane disposed between the anode and the cathode, and a stack that is an intermediate laminated in the manufacturing process of the membrane electrode assembly.

Description

Method for manufacturing membrane electrode assembly and stacked body

Technical Field

This application claims priority and benefit from korean patent application No. 10-2018-.

The present specification relates to a method for manufacturing a membrane electrode assembly and a laminate. Specifically, the present specification relates to a method of manufacturing a membrane electrode assembly including an anode, a cathode, and an electrolyte membrane disposed between the anode and the cathode, and a laminate which is an intermediate body laminated in the manufacturing process of the membrane electrode assembly.

Background

Recently, since the exhaustion of existing energy sources such as petroleum or coal is expected, the demand for energy capable of replacing these energy sources is increasing, and as one of the alternative energy sources, attention to fuel cells, metal secondary batteries, flow batteries, and the like has been focused.

As one of these alternative energy sources, since the fuel cell is highly efficient and does not discharge, for example, NO_xAnd SO_xAnd the fuel used is abundant, so that active research on fuel cells is being conducted.

Fig. 1 schematically illustrates the electricity generation principle of a fuel cell in which the most basic unit generating electricity is a Membrane Electrode Assembly (MEA) composed of an electrolyte membrane (M) and an anode (a) and a cathode (C) formed on both surfaces of the electrolyte membrane (M). Referring to fig. 1 showing the principle of electricity generation of a fuel cell, an oxidation reaction of fuel (F), such as hydrogen or hydrocarbons (e.g., methanol and butane), occurs in an anode (a), and as a result, hydrogen ions (H) are generated⁺) And electron (e)^-) The hydrogen ions move to the cathode (C) through the electrolyte membrane (M). In the cathode (C), hydrogen ions transferred through the electrolyte membrane (M), an oxidant (O) such as oxygen, and electrons react to generate water (W). By this reaction, the electrons move to an external circuit.

Disclosure of Invention

Technical problem

The present specification has been made in an effort to provide a method of manufacturing a membrane electrode assembly and a laminate. Specifically, the present specification has been made in an effort to provide a method of manufacturing a membrane electrode assembly including an anode, a cathode, and an electrolyte membrane disposed between the anode and the cathode, and a laminate which is an intermediate laminated in the manufacturing process of the membrane electrode assembly.

Technical scheme

The present specification provides a method of manufacturing a membrane electrode assembly, the method comprising: manufacturing a first electrode film by forming a first electrode catalyst layer on a first release film; manufacturing a second electrode film by forming a second electrode catalyst layer on the second release film; preparing an electrolyte membrane; disposing a first electrode film and a second electrode film on both surfaces of an electrolyte film such that the surfaces on which the first electrode catalyst layer and the second electrode catalyst layer are formed face the electrolyte film, respectively; forming a laminate by additionally providing a pattern paper having a non-heat-conductive property on a surface of the first release film opposite to a surface thereof on which the first electrode catalyst layer is formed; thermally bonding the laminated body with a pressure between the two transfer substrates after disposing the laminated body between the two transfer substrates having thermal conductivity; and forming an assembly by removing the pattern paper, the first release film and the second release film from the heat-bonded laminate.

Further, the present specification provides a laminate comprising: a first electrode film including a first release film and a first electrode catalyst layer disposed on the first release film; a second electrode film including a second release film and a second electrode catalyst layer disposed on the second release film; an electrolyte membrane disposed between the first electrode film and the second electrode film; and a pattern paper having a non-heat-conductive property and disposed on the first release film, wherein surfaces on which the first electrode catalyst layer and the second electrode catalyst layer are formed are disposed to face the electrolyte membrane, respectively, and the pattern paper is disposed on a surface of the first release film opposite to the surface on which the first electrode catalyst layer is formed.

Advantageous effects

Based on the method according to the exemplary embodiment of the present description, patterns may be formed on the electrodes and the electrolyte membrane to improve the interfacial bonding between the electrodes and the electrolyte membrane.

Based on the method according to the exemplary embodiment of the present description, a pattern may be formed on the electrode and the electrolyte membrane to increase a contact area between the electrode and the electrolyte membrane, thereby improving performance.

Drawings

Fig. 1 is a schematic diagram showing the electricity generation principle of a fuel cell.

Fig. 2 is a diagram schematically showing the structure of a membrane electrode assembly for a fuel cell.

Fig. 3 is a diagram schematically showing an example of the fuel cell.

Fig. 4 is a diagram schematically illustrating a stack of membrane electrode assemblies in the related art.

Fig. 5 is a view schematically showing a pattern manufacturing method of a membrane electrode assembly according to the present specification.

Fig. 6 is a diagram showing a process of a thermal bonding step according to the present specification.

Fig. 7 is a diagram illustrating pattern paper used in example 1 and example 2.

Fig. 8 is a diagram showing a pattern paper used in example 3.

Fig. 9 is a graph comparing the performance of the membrane electrode assemblies according to example 1 and comparative example 1 under the condition of 100% Relative Humidity (RH).

Fig. 10 is a graph comparing the performance of the membrane electrode assemblies according to example 1 and comparative example 1 under the condition of 50% Relative Humidity (RH).

Fig. 11 is a graph comparing the performance of the membrane electrode assemblies according to example 1 and comparative example 1 under the condition of 32% Relative Humidity (RH).

Fig. 12 is a comparative graph of the performance of the membrane electrode assemblies according to examples 2 and 3 and comparative example 2 under the condition of 100% Relative Humidity (RH).

Fig. 13 is a comparative graph of the performance of the membrane electrode assembly according to examples 2 and 3 and comparative example 2 under the condition of 50% Relative Humidity (RH).

Fig. 14 is a comparative graph of the performance of the membrane electrode assembly according to examples 2 and 3 and comparative example 2 under the condition of 32% Relative Humidity (RH).

Fig. 15 is a graph showing the durability of the membrane electrode assembly in the fuel cell state measured by the RH cycle test.

Fig. 16 is a comparative graph of the performance of the membrane electrode assembly according to example 2 and comparative examples 3 and 4 under the condition of 100% Relative Humidity (RH).

Fig. 17 is a comparative graph of the performance of the membrane electrode assembly according to example 2 and comparative examples 3 and 4 under the condition of 50% Relative Humidity (RH).

Fig. 18 is a comparative graph of the performance of the membrane electrode assembly according to example 2 and comparative examples 3 and 4 under the condition of 32% Relative Humidity (RH).

10A: buffer substrate

11A: flat substrate

20A: pattern paper

30A: electrode film

31A: electrode catalyst layer

32A: release film

40A, 100: electrolyte membrane

60: stacked body

70A: transfer substrate

70: oxidant supply part

80: fuel supply part

81: fuel tank

82: pump and method of operating the same

200: cathode catalyst layer

210: anode catalyst layer

400: cathode gas diffusion layer

410: anode gas diffusion layer

500: cathode electrode

510: anode

Detailed Description

The present specification is described in detail hereinafter.

[ method for producing Membrane electrode Assembly ]

The present specification provides a method of manufacturing a membrane electrode assembly, the method comprising:

manufacturing a first electrode film by forming a first electrode catalyst layer on a first release film;

manufacturing a second electrode film by forming a second electrode catalyst layer on the second release film;

preparing an electrolyte membrane;

disposing a first electrode film and a second electrode film on both surfaces of an electrolyte film such that the surfaces on which the first electrode catalyst layer and the second electrode catalyst layer are formed face the electrolyte film, respectively;

forming a laminate by additionally providing a pattern paper having a non-heat-conductive property on a surface of the first release film opposite to a surface thereof on which the first electrode catalyst layer is formed;

thermally bonding the laminated body with a pressure between the two transfer substrates after disposing the laminated body between the two transfer substrates having thermal conductivity; and

an assembly is formed by removing the pattern paper, the first release film and the second release film from the heat-bonded laminate.

[ production of first electrode film and second electrode film ]

The manufacturing method of the membrane electrode assembly according to the present specification includes: manufacturing a first electrode film by forming a first electrode catalyst layer on a first release film; and manufacturing a second electrode film by forming a second electrode catalyst layer on the second release film.

The material of the first and second release films is not particularly limited as long as the material can support the electrode catalyst layer to be formed on the substrate and has good release properties during transfer to the electrolyte membrane, and typical release films used in the art may be employed.

The first electrode catalyst layer and the second electrode catalyst layer may each be formed by using an electrode composition, and a method of forming the first electrode catalyst layer and the second electrode catalyst layer may be performed by a typical method known in the art, for example, a method such as spray coating, tape casting, screen printing, blade coating, comma coating, or die coating (die coating) may be used.

The electrode composition may be variously applied according to the type and use of the electrode catalyst layer, and the electrode composition may include a catalyst, a polymer ionomer, and a solvent.

The type of the catalyst is not particularly limited, and a catalyst used in the art may be employed. For example, the catalyst may include metal particles selected from the group consisting of platinum, ruthenium, osmium, platinum-ruthenium alloys, platinum-osmium alloys, platinum-palladium alloys, and platinum-transition metal alloys. In this case, the metal particles may be solid particles, hollow metal particles, bowl-shaped particles, core-shell particles, or the like.

The catalyst may be used not only as it is but also while being supported on a carbon-based carrier.

As the carbon-based support, as a carbon-based material, preferred examples may include any one selected from the group consisting of graphite, carbon black, acetylene black, superconducting acetylene black, ketjen black, activated carbon, mesoporous carbon, carbon nanotubes, carbon nanofibers, carbon nanohorns, carbon nanorings, carbon nanowires, fullerene (C60), and super P black, or a mixture of two or more thereof.

As the polymer ionomer, Nafion ionomer or sulfonated polymer such as sulfonated polytrifluoroethylene may be representatively used.

The solvent is not particularly limited, and a solvent used in the art may be used. For example, as the solvent, any one selected from the group consisting of water, butanol, isopropanol, methanol, ethanol, n-propanol, n-butyl acetate, glycerol and ethylene glycol, or a mixture of two or more thereof may be preferably used.

[ preparation of electrolyte Membrane ]

The manufacturing method of the membrane electrode assembly according to the present specification may include preparing an electrolyte membrane.

In the preparation of the electrolyte membrane, an externally manufactured electrolyte membrane may be purchased, or the electrolyte membrane may be directly manufactured.

The electrolyte membrane may be a reinforced membrane including a polymer having an ion-conductive polymer and produced by impregnating the ion-conductive polymer in pores of a porous support, or may be a pure membrane having no porous support but produced by solidifying the ion-conductive polymer.

The type of the porous support is not particularly limited, but may be a substance derived from polyolefins such as polypropylene (PP) and Polyethylene (PE), and fluorocarbons such as Polytetrafluoroethylene (PTFE), or a mixture thereof. Further, preferably, the porosity of the porous support is 60% to 90%, and the permeability (time for 500cc of air to pass through the porous support) is 15 seconds to 30 seconds.

The ion-conductive polymer is not particularly limited as long as the polymer is a substance capable of exchanging ions, and ion-conductive polymers generally used in the art may be used.

The ion-conducting polymer may be a hydrocarbon-based polymer, a partially fluorine-based polymer, or a fluorine-based polymer.

The hydrocarbon-based polymer may be a hydrocarbon-based sulfonated polymer having no fluorine group, on the contrary, the fluorine-based polymer may be a sulfonated polymer saturated with a fluorine group, and a part of the fluorine-based polymer may be a sulfonated polymer unsaturated with a fluorine group.

The ion conductive polymer may be one or more polymers selected from the group consisting of a perfluorosulfonic acid-based polymer, a hydrocarbon-based polymer, an aromatic sulfone-based polymer, an aromatic ketone-based polymer, a polybenzimidazole-based polymer, a polystyrene-based polymer, a polyester-based polymer, a polyimide-based polymer, a polyvinylidene fluoride-based polymer, a polyether sulfone-based polymer, a polyphenylene sulfide-based polymer, a polyphenylene ether-based polymer, a polyphosphazene-based polymer, a polyethylene naphthalate-based polymer, a polyester-based polymer, a doped polybenzimidazole-based polymer, a polyether ketone-based polymer, a polyether ether ketone-based polymer, a polyphenylquinoxaline-based polymer, a polysulfone-based polymer, a polypyrrole-based polymer, and a polyaniline-based polymer. The polymer may be sulfonated for use, and may be a single copolymer, an alternating copolymer, a random copolymer, a block copolymer, a multiblock copolymer, or a graft copolymer, but is not limited thereto.

The ion conductive polymer may be a polymer having cationic conductivity, and may include, for example, at least one of a perfluorosulfonic acid-based polymer, sulfonated polyether ether ketone (sPEEK), sulfonated polyether ketone (sPEEK), poly (vinylidene fluoride) -graft-poly (styrene sulfonic acid) (PVDF-g-PSSA), and sulfonated poly (fluorenylether ketone).

[ arrangement of first electrode film and second electrode film ]

The manufacturing method of the membrane electrode assembly according to the present specification may include disposing a first electrode film and a second electrode film on both surfaces of an electrolyte membrane. In this case, it is preferable that the surfaces on which the first electrode catalyst layer and the second electrode catalyst layer are formed are disposed to face the electrolyte membrane, respectively.

[ formation of a laminate ]

As shown in fig. 4, in the related art, there is no separate unit for imparting a pattern to the stack during the manufacturing process of the membrane electrode assembly.

The manufacturing method of a membrane electrode assembly according to the present specification may include forming a laminate by additionally providing a pattern paper having a non-heat-conductive property on a surface of the first release film opposite to a surface thereof on which the first electrode catalyst layer is formed. Fig. 5 shows the structure of a laminate additionally containing a pattern paper.

In the formation of the laminate, by additionally providing a pattern paper before the laminate is thermally bonded, a pattern can be imparted to the laminate by a simple process.

In the formation of the laminate, when the electrode catalyst layers are thermally bonded to both surfaces of the electrolyte membrane, by inserting a thin pattern paper only on one side of the electrode catalyst layer, a pattern based on the pattern paper is formed not only on the electrode catalyst layer on the side where the pattern paper is laminated but also on the electrode catalyst layer on the other side where the electrolyte membrane and the pattern paper are not laminated.

An advantage of a laminate imparted with a pattern by the patterned paper is that the interfacial adhesion to adjacent layers is improved. Specifically, the laminate is advantageous in that the adhesion at the interface between the first electrode catalyst layer and the electrolyte membrane and the adhesion at the interface between the second electrode catalyst layer and the electrolyte membrane are both improved.

The laminate imparted with a pattern by the pattern paper has an advantage in that the contact area with the adjacent layer is increased. Specifically, the laminated body is advantageous in that the contact area at the interface between the first electrode catalyst layer and the electrolyte membrane and the contact area at the interface between the second electrode catalyst layer and the electrolyte membrane are both increased.

[ Pattern paper ]

The thickness of the pattern paper is not particularly limited as long as the thickness does not interfere with the transfer of heat for thermal bonding from the transfer substrate to the electrode catalyst layer and the electrolyte membrane, and may be 10nm or more and 1mm or less, specifically 200 μm or more and 800 μm or less, preferably 400 μm or more and 700 μm or less.

According to exemplary embodiments of the present description, a pattern paper may include a base material and a pattern disposed on the base material.

The substrate is not particularly limited as long as the substrate has a non-heat-conductive property, and may be, for example, cloth, non-woven fabric, plastic film, or paper.

The pattern may include an opening of a closed figure and a pattern line surrounding the opening.

The composition for forming the pattern line is the same material as the substrate, or includes a polymer, and in the case of the polymer, the content of the polymer may be 1% to 50% based on the total weight of the composition.

The method of forming the pattern lines on the substrate is not particularly limited, but the pattern lines may be formed by roll printing (roll printing), an ink jet method, a woven pattern (cloth), or the like.

The line width of the pattern line is not particularly limited, but may be 100nm or more and 1mm or less, 1 μm or more and 500 μm or less, and 10 μm or more and 200 μm or less.

The pattern lines may be continuous pattern lines or discontinuous pattern lines, and may be linear shapes, curved lines, zigzag shapes, and the like. Preferably, the pattern line may be a continuous linear pattern.

The pattern may be a regular pattern, an irregular pattern, or a mixed pattern thereof, and may preferably be a regular pattern. For example, the pattern may be a grid pattern.

The pattern may further include protrusions in the openings. The cross section of the protrusion may be circular or polygonal, and the size of the protrusion may be 50nm or more and 200 μm or less. In this case, the size of the protrusion means a distance between the longest two points on the cross section.

According to another exemplary embodiment of the present specification, the pattern paper may be composed of openings that leave continuous patterns in the base material and cut off the remaining portions.

According to still another exemplary embodiment of the present specification, the pattern paper may preferably be a cloth having a woven pattern, and particularly may be a polyester cloth having a woven pattern. In this case, the line width and form of the pattern are the same as defined above.

The pattern interval is not particularly limited, and may be 50 μm to 3mm, 500 μm to 1.5mm, 800 μm to 1 mm.

[ Heat bonding step ]

The manufacturing method of the membrane electrode assembly according to the present specification may include thermally bonding the stacked body. Specifically, the thermal bonding of the laminate may be such that the laminate is disposed between two transfer substrates having thermal conductivity and then the laminate is thermally bonded with the pressure between the two transfer substrates.

In the thermal bonding of the laminated body, a flat substrate and a buffer substrate may be additionally included between the two transfer substrates. Specifically, it may have a structure of transfer substrate/buffer substrate/flat substrate/laminate/flat substrate/buffer substrate/transfer substrate.

The transfer substrate may be a metal substrate having thermal conductivity, and the material thereof is not particularly limited, and may be aluminum, stainless steel, titanium alloy, or the like.

The transfer substrate is a member provided in the thermal bonding device, and the laminate to be thermally bonded is provided and inserted between the transfer substrates provided in the thermal bonding device, and then the thermal bonding device is driven to narrow the gap between the two transfer substrates while applying pressure to the inserted laminate.

The temperature of the transfer substrate is not particularly limited as long as the first electrode catalyst layer and the second electrode catalyst layer can be bonded to the electrolyte membrane, and may be, for example, 100 ℃ or more and 150 ℃ or less.

The pressure of the transfer substrate is not particularly limited as long as the first electrode catalyst layer and the second electrode catalyst layer can be bonded to the electrolyte membrane, and may be, for example, 0.5 ton or more and 3.0 ton or less.

In order to prevent wrinkles from being generated by using a cloth material for the buffer substrate, the pattern paper, and the like, a flat substrate is used, and the material of the flat substrate is not particularly limited, but may be a glass fiber film. Fig. 6 shows the course of the thermal bonding step according to the present description.

The buffer substrate is used to prevent the membrane electrode assembly from being damaged by the pattern, and the material of the buffer substrate is not particularly limited, but may be a cloth material such as polyester.

[ formation of Assembly ]

The manufacturing method of a membrane electrode assembly according to the present specification may include forming an assembly by removing the pattern paper, the first release film, and the second release film from the heat-bonded laminate.

A method of removing the pattern paper, the first release film and the second release film from the heat-bonded laminate is not particularly limited.

The assembly obtained by removing the pattern paper, the first release film, and the second release film from the heat-bonded laminate is in a state in which the first electrode catalyst layer and the second electrode catalyst layer are provided on both surfaces of the electrolyte membrane.

The manufacturing method of a membrane electrode assembly according to the present specification may further include further forming a gas diffusion layer on each of the first electrode catalyst layer and the second electrode catalyst layer of the manufactured assembly.

[ laminate ]

The present specification provides a laminated body including a first electrode film, a second electrode film, an electrolyte film, and a pattern paper.

The description about the manufacturing method of the membrane electrode assembly described above can be applied to the description about the laminated body.

[ first electrode film/second electrode film ]

The first electrode film may include a first release film and a first electrode catalyst layer disposed on the first release film.

The second electrode film may include a second release film and a second electrode catalyst layer disposed on the second release film.

One of the first electrode catalyst layer and the second electrode catalyst layer may be used as a catalyst layer of an anode or a catalyst layer of a cathode, and the other may be used as an electrode catalyst layer that is not selected as a catalyst layer of an anode or a catalyst layer of a cathode. In this case, an oxidation reaction of the fuel occurs in the catalyst layer of the anode, and a reduction reaction of the oxidant occurs in the catalyst layer of the cathode.

In the exemplary embodiments of the present specification, each of the first electrode catalyst layer and the second electrode catalyst layer may have a thickness of 3 μm or more and 30 μm or less. In this case, the thicknesses of the catalyst layer of the anode and the catalyst layer of the cathode may be the same as or different from each other.

[ electrolyte Membrane ]

The electrolyte membrane may be disposed between the first electrode film and the second electrode film.

The surfaces on which the first electrode catalyst layer and the second electrode catalyst layer are formed may be disposed to face the electrolyte membrane, respectively.

[ Pattern paper ]

The pattern paper may be disposed on the first release film. Specifically, the pattern paper may be disposed on a surface of the first release film opposite to a surface thereof on which the first electrode catalyst layer is formed.

The pattern paper may have a non-heat-conductive property. In this specification, the non-thermal conductivity may include a case where there is no thermal conductivity at all or slightly. Specifically, the non-thermal conductivity means a thermal conductivity of 2W/mK or less, more specifically, a thermal conductivity of 0 to 0.5W/m K.

[ Membrane electrode Assembly/cell ]

The present specification provides an electrochemical cell comprising: an anode; a cathode; and an electrolyte membrane disposed between the anode and the cathode, wherein the electrochemical cell includes a membrane electrode assembly manufactured by the manufacturing method of the membrane electrode assembly.

The cathode refers to an electrode that receives electrons and is reduced when the battery is discharged, and may be an anode (oxidation electrode) that is oxidized and releases electrons when the battery is charged. The anode refers to an electrode that is oxidized and releases electrons when the battery is discharged, and may be a cathode (reduction electrode) that receives electrons and is reduced when the battery is charged.

The electrochemical cell refers to a cell using a chemical reaction, and the type thereof is not particularly limited as long as the cell includes a membrane electrode assembly manufactured by the manufacturing method, and for example, the electrochemical cell may be a fuel cell, a metal secondary cell, or a flow battery.

The present specification provides an electrochemical cell module including electrochemical cells as unit cells.

An electrochemical cell module may be formed by stacking cells by interposing bipolar plates between unit cells according to an exemplary embodiment of the present application.

The battery module may be particularly used as a power source for an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

The present specification provides a membrane electrode assembly manufactured by a method of manufacturing a membrane electrode assembly.

The present specification provides a fuel cell including the membrane electrode assembly.

Fig. 2 schematically shows the structure of a membrane electrode assembly for a fuel cell, which may include an electrolyte membrane 100, and a cathode 500 and an anode 510 facing each other across the electrolyte membrane 100. In the cathode, a cathode catalyst layer 200 and a cathode gas diffusion layer 400 may be provided in order from the electrolyte membrane 100, and in the anode, an anode catalyst layer 210 and an anode gas diffusion layer 410 may be provided in order from the electrolyte membrane 100.

Fig. 3 schematically shows the structure of a fuel cell including a stack 60, an oxidant supply portion 70, and a fuel supply portion 80.

The stack 60 includes one membrane electrode assembly or two or more membrane electrode assemblies as described above, and when two or more membrane electrode assemblies are included, the stack 60 includes a separator disposed between the membrane electrode assemblies. The separator serves to prevent the membrane electrode assemblies from being electrically connected to each other, and to transmit fuel and oxidant supplied from the outside to the membrane electrode assemblies.

The oxidizer supplying part 70 serves to supply an oxidizer to the stack 60. As the oxidant, oxygen is representatively used, and oxygen or air may be used by injecting the oxygen or air into the oxidant supply portion 70.

The fuel supply portion 80 is for supplying fuel to the stack 60, and may be composed of a fuel tank 81 that stores fuel and a pump 82 that supplies the fuel stored in the fuel tank 81 to the stack 60. As fuel, gaseous or liquid hydrogen or hydrocarbon fuels can be used. Examples of hydrocarbon fuels may include methanol, ethanol, propanol, butanol, or natural gas.

[ examples ]

Hereinafter, the present specification will be described in more detail by way of examples. However, the following examples are provided only to illustrate the present specification and are not intended to limit the present specification.

[ examples ]

[ preparation example 1]

Production of electrolyte membrane 1

The reaction mixture was prepared under a nitrogen atmosphere by placing hydroquinone sulfonic acid potassium salt, 4' -difluorobenzophenone, and 3, 5-bis (4-fluorobenzoyl) phenyl (4-fluorophenyl) methanone into a 1L round bottom flask equipped with a dean-stark trap and a condenser, and using potassium carbonate as a catalyst in dimethyl sulfoxide (DMSO) and benzene solvent. Next, the reaction mixture was further stirred at a temperature of 150 ℃ or less to remove water in the reaction bath while refluxing benzene, the reaction temperature was raised to 200 ℃ or less, and the obtained product was subjected to polycondensation reaction. Next, after the temperature of the reactants was lowered to room temperature and the product was diluted by further adding DMSO thereto, the diluted product was injected into an excess of methanol, and the copolymer was separated from the solvent. Thereafter, a branched sulfonated multiblock copolymer in which hydrophobic blocks and hydrophilic blocks are alternately linked by chemical bonds is manufactured by drying the copolymer obtained by filtration using water in a vacuum oven. In this case, the sulfonated multiblock copolymer produced is referred to as a first polymer. The first polymer is coated by bar coating with a coater to form the electrolyte membrane 1.

[ preparation example 2]

Production of electrolyte membrane 2

The electrolyte membrane 2 is manufactured by impregnating a polyolefin-based porous support having a porosity of 60% to 70% in a solution containing the above-described first polymer.

[ example 1]

An ionomer (product name: Nafion D2021), monohydric alcohol, and Pt/C catalyst (product name: Tanaka10V50E) were mixed/dispersed, an electrode catalyst layer was coated with the mixture by a spray coating method, and the electrode catalyst layer was dried, so that an electrode catalyst layer having a thickness of 10 μm was formed on a substrate (PTFE) having a thickness of 200 μm, thereby manufacturing an electrode film.

After electrode films were provided on both surfaces of the electrolyte membrane 1 manufactured in production example 1, a laminated body was manufactured by laminating the pattern paper in fig. 7 on the base material on only the electrode film side. After a flat substrate (glass fiber) and a cushion substrate (polyester fiber cloth) were laminated on both surfaces of the laminate, the substrates were disposed between two transfer substrates that were hot-pressed, and were thermally bonded by applying a pressure of 2.7 tons at 140 ℃.

After that, the patterned paper and the base material of the electrode film are removed to produce a module in which the electrode catalyst layer is transferred to the electrolyte membrane. The pattern paper has a thickness of 0.5mm and is formed of a polyester material, and the pattern is woven on the base material and has a pattern form in fig. 7. The pattern had a line thickness of about 200 μm and a line spacing of 1 mm. In this case, the thermal conductivity is 0.1W/m K to 0.4W/m K.

[ example 2]

A module was manufactured in the same manner as in example 1, except that the electrolyte membrane 2 prepared in preparation example 2 was used as an electrolyte membrane and the electrolyte membrane 1 was not used as an electrolyte membrane.

[ example 3]

The assembly was manufactured in the same manner as in example 2, except that the pattern paper in fig. 8 was used instead of the pattern paper in fig. 7.

The pattern paper has a thickness of 0.5mm and is formed of a polyester material, and the pattern is woven on the base material and has a pattern form in fig. 8. The pattern had a line thickness of about 200 μm and a line spacing of 1 mm. In this case, the thermal conductivity is 0.1W/m K to 0.4W/m K.

Comparative example 1

The assembly was manufactured in the same manner as in example 1, except that the substrates were thermally bonded without the pattern paper.

Comparative example 2

The assembly was manufactured in the same manner as in example 2, except that the substrates were thermally bonded without the pattern paper.

Comparative example 3

After the electrode film was manufactured in example 1, the same pattern as that of the pattern paper in fig. 7 was formed on the electrode catalyst layer using the same composition as that of the electrode catalyst layer by a stamp method (pattern was formed by arranging patterns and stamping the patterns like stamp).

After the electrode films formed with patterns were disposed on both surfaces of the electrolyte membrane 2 manufactured in preparation example 2, the electrode films were disposed between two transfer substrates that were hot-pressed, and were thermally bonded by applying a pressure of 2.7 tons thereto at 140 ℃.

After that, a component in which the electrode catalyst layer is transferred to the electrolyte membrane is manufactured by removing the base material of the electrode membrane.

Comparative example 4

A laminate in which the electrode films manufactured in example 1 were disposed on both surfaces of the electrolyte membrane 1 manufactured in preparation example 1 was manufactured. An aluminum foil having the same pattern as that in fig. 7 was attached to the two transfer substrates that were hot-pressed, and then the laminate was disposed between the transfer substrates, and then thermally bonded by applying a pressure of 2.7 tons thereto at 140 ℃.

After that, by removing the base material of the electrode film, a component in which the electrode catalyst layer is transferred to the electrolyte film is produced.

[ Experimental example 1]

Measurement of current density

Results of comparative examples 1 and 2 and examples 1 to 3 are shown in fig. 9 to 14 according to relative humidity, and particularly, comparative results of current density at 0.6V based on comparative example 1 are shown in table 1 below.

[ Table 1]

As can be seen from fig. 9 to 14 and table 1, the membrane electrode assembly using the pattern has similar performance at the existing RH 100% or RH 50%, but the performance is improved in the low humidity region. This means that, even in the case where a small amount of moisture is present in the membrane electrode assembly, ions are effectively moved by an increase in the contact area and a decrease in contact resistance during transfer, with the result that performance is improved.

Results of comparative examples 3 and 4 and example 2 are shown in fig. 16 to 18 according to relative humidity, and particularly, comparative results of current density at 0.6V based on comparative example 4 are shown in the following table 2.

[ Table 2]

As can be seen from fig. 16 to 18 and table 2, the performance in comparative example 3 in which a pattern was placed in the electrode was higher than that in comparative example 4 in which an aluminum foil was used, but the performance in example 2 was improved by 37% to 68% as compared with comparative example 4, and in particular, it was confirmed that the lower the humidity was, the greater the improvement in performance was. From this, it can be seen that the performance of the membrane electrode assembly using the pattern paper is more improved than that based on other methods. The improvement in performance is a result that can be obtained by an increase in the contact area and a decrease in contact resistance due to the pattern during transfer.

[ Experimental example 2]

Relative humidity cycle experiment (RH cycle test)

In this case, the RH cycle measures the durability of a Membrane Electrode Assembly (MEA) in a fuel cell state, and the durability is measured by injecting hydrogen and nitrogen into an anode at a flow rate of 0.95 standard liter per minute (slm) under a condition of 80 ℃, injecting nitrogen into a cathode at a flow rate of 1.0slm, and switching humidification and non-humidification at intervals of 2 minutes.

Excellent mechanical durability can be confirmed by RH cycling of the membrane electrode assembly, and high RH cycling means that the membrane electrode assembly has high durability. In this case, the RH cycle refers to the number of cycles until damage to the membrane electrode assembly, which is too strong for the membrane electrode assembly to be used, occurs.

To measure whether the membrane electrode assembly was damaged during RH cycling, Linear Sweep Voltammetry (LSV) was used, and hydrogen crossover (crossover) was measured at 0.1 to 0.4V (2mV/s) by injecting hydrogen into the anode at a flow rate of 0.2slm and nitrogen into the cathode at a flow rate of 0.2 slm.

When the crossover value of hydrogen increases in the RH cycle, it can be seen that the membrane electrode assembly is damaged, and the degree to which the membrane electrode assembly is damaged can be determined according to the degree to which the crossover value of hydrogen increases.

The results are shown in FIG. 15.

As can be seen from FIG. 15, the MEA was of a type that satisfied the DOE standard (U.S. department of energy standard, 2mA/cm at 20000 cycles²Cross value below) of the filmAs for the electrode assembly, considering that the results of the membrane electrode assembly in example 3 and the membrane electrode assembly in comparative example 2, which was transferred by using the pattern paper, were similar to each other, it was confirmed that the durability was not affected since the membrane electrode assembly was hardly damaged by the pattern.

Claims

1. A method of manufacturing a membrane electrode assembly, the method comprising:

preparing an electrolyte membrane;

disposing the first electrode film and the second electrode film on both surfaces of the electrolyte film such that the surfaces on which the first electrode catalyst layer and the second electrode catalyst layer are formed face the electrolyte film, respectively;

forming a laminate by additionally providing a pattern paper having a non-heat-conductive property on a surface of the first release film opposite to the surface on which the first electrode catalyst layer is formed;

thermally bonding the laminated body with a pressure between two transfer substrates having thermal conductivity after disposing the laminated body between the two transfer substrates; and

forming an assembly by removing the pattern paper, the first release film and the second release film from the heat-bonded laminate.

2. The method for manufacturing a membrane electrode assembly according to claim 1, wherein the thickness of the pattern paper is 10 μm or more and 1mm or less.

3. The manufacturing method of a membrane electrode assembly according to claim 1, wherein the pattern paper comprises a base material and a pattern provided on the base material.

4. The method for manufacturing a membrane electrode assembly according to claim 3, wherein the substrate is cloth, nonwoven fabric, plastic film, or paper.

5. The manufacturing method of a membrane electrode assembly according to claim 3, wherein the interval of the pattern is 100 μm or more and 3mm or less.

6. The manufacturing method of a membrane electrode assembly according to claim 3, wherein the pattern is a mesh pattern.

7. The manufacturing method of a membrane electrode assembly according to claim 1, wherein the pattern includes an opening of a closed figure and a pattern line surrounding the opening.

8. The manufacturing method of a membrane electrode assembly according to claim 7, wherein the pattern further includes protrusions in the openings.

9. The manufacturing method of a membrane electrode assembly according to claim 1, wherein the pattern paper is a cloth having a woven pattern.

10. A laminate, comprising:

a first electrode film including a first release film and a first electrode catalyst layer disposed on the first release film;

a second electrode film including a second release film and a second electrode catalyst layer disposed on the second release film;

an electrolyte membrane disposed between the first electrode membrane and the second electrode membrane; and

a pattern paper having a non-heat-conductive property and disposed on the first release film,

wherein surfaces on which the first electrode catalyst layer and the second electrode catalyst layer are formed are disposed to face the electrolyte membrane, respectively, and

the pattern paper is disposed on a surface of the first release film opposite to a surface on which the first electrode catalyst layer is formed.